What is BS IEC 61156‑1‑4 - Multicore and symmetrical pair/quad cables for digital communications about?
BS IEC 61156 is a series on multicore and symmetrical pair/quad cables for digital communications. Multicore and symmetrical pair/quad cables are a type of cable that combines multiple signals or power feeds into a single jacketed cable.
BS IEC 61156‑1‑4 specifies a method to assess the thermal behaviour of cables arranged in bundles, for digital communications. A method is described to determine the temperature increase in cable bundles for certain remote powering currents as a basis to analyse the expected performance under several test arrangements described in standards dealing with the installation of cabling systems.
BS IEC 61156‑1‑4 is only intended to provide guidance to assess the thermal behaviour of cables for digital communications in reference to environmental conditions and arrangements. BS IEC 61156‑1‑4 s therefore not intended to become a type of test method.
Who is BS IEC 61156‑1‑4 - Multicore and symmetrical pair/quad cables for digital communications for?
BS IEC 61156‑1‑4 on multicore and symmetrical pair/quad cables is useful for:
- Telecommunication equipment manufacturers
- Telecommunication component manufacturers
- Design engineers
- Quality control personnel
- Research and development facilities
Why should you use BS IEC 61156‑1‑4 - Multicore and symmetrical pair/quad cables for digital communications?
The use of remote powering causes a temperature rise in cables installed in bundles. BS IEC 61156‑1‑4 specifies a method to assess the temperature increase in cable bundles by measuring the temperature change using thermocouples placed on the sheath of the cable at the centre of the bundle. Several test arrangements are considered as well as current values. The test arrangements are considered are free air cable tray conduits conduit with sealed ends.
The temperature as described in BS IEC 61156‑1‑4 is of utmost importance in terms of the suitability of the insulation material at the interface with the conductor in order to avoid overheating and consecutive degradation of the insulation and transmission characteristics. In addition, health and safety issues may arise, such as a meltdown and the potential danger of self-ignition. Using BS IEC 61156‑1‑4 you can understand guidance to assess the thermal behaviour of cables for digital communications in reference to environmental conditions and arrangements.
What’s changed since the last update?
BS IEC 61156‑1‑4:2018 supersedes DD IEC/PAS 61156‑1‑4:2010. BS IEC 61156‑1‑4:2018 includes some technical changes with respect to DD IEC/PAS 61156‑1‑4:2010. These include:
- Several test arrangements are considered
- The mathematical approach was revised.

